Question

Describe an example from the fossil record that shows how life has changed over time.

Short answer

The examples of fossil records can be single-celled organisms giving rise to complex animals and plants that showed how life has evolved. Many organisms became extinct and are buried by sediments.

The fossil record provides valuable information or complex data worldwide, such as insects well-preserved in fossilized tree sap and exhibits that life on Earth has evolved and has changed over time.

Step-by-step solution

Meaning of Fossil

Fossils are the remnant or traces of a dead and decaying organism that can be found in stratified rocks.They are the mineralized form of an organism formed from bones and shells that cannot decay easily.

They provide preserved evidence that life existed from a past geological age, including remains and impressions of an animal or plant that has been embedded in Earth’s crust.

Sedimentary rocks

The rich source of fossils is sedimentary rock. The fossil record depends on many horizontal layers called strata,in which fossils have aggregated in sedimentary rock layers.

Sedimentary layers are arranged on one another over a long exposure, and sedimentary rock is formed by squeezing the weight of the top layers on the lowest layer.

Radiometric dating

The fossil’s age is estimated by radiometric dating methods,depending on the natural radioactive decay of radioactive isotopes such as carbon or potassium. It is not influenced by temperature, pressure, climate, and rainfall, and the rate of decay is determined by half-life.

For example, the half-life of Uranium-238 is 4.5 billion years due to slow decay.

Examples of the fossil records are stratified rocks exposed in the walls of the Grand Canyon, complex plants, and animals evolving from the unicellular organism showed that life on Earth was once different from today’s life on the planet.